Lifting jack



Patented Feb. 10, 1931 narran rares --epnfre'r Ferca i J. EODTJEAN AND HAROLD V. CLARK, OF- ALLIANCE, OHIO, ASSIGNORS TO THE BCKEYE JACK MANUFACTURING COMPANY, OF ALLIANCE, OHIO, A CORPORA- TION OF OHIO nrrfrrnef JAcK Application mea october e, 192e. serial Na'ieoaeo. i

This invention relates to jacks, and particularly to improved form of screw jack which is of special value in handling heavy loads.

We provide a screw jack having a base with a housing projecting therefrom, the housing having an open slot in one side thereof, a screw within the housing and a nut for the screw, the nuthaving a projecting portion which lies in the slot. Preferably the nut extends substantially the full length of the housing, as does its projecting portion which engages the slot. This projecting portion is provided with a lift member which is adj nstable to different vertical positions and in i5 this manner a very simple and effective form acl; 1s secured. Preferably the base 1sY of j provided .with an operating shaft having a bevel pinion thereon, this pinion engaging a bevel gear which lies in a horizontal plane and is connected to the screw through sun and planet gearing.

ln the accomp anying Vdrawings, which'illustrate a present preferred embodiment of the invention, Y

Figure 1 is a top plan- View of a jack constructed according to onr invention;

YFigure 2 is a side elevation thereof, partly broken away, and

Figure 3 is a horizontal` section through a modified form of jack.

ln the illustrated embodiment of the invention there is shown a hollow base 2 having an upstanding housing 3 made integral therewith. Ribs 4 are provided for strengthening the housing. The housing is generally circular when viewed in plan, but it is provided with a slot 5 in one side thereof extending from top to bottom of the housing. Y

Lying within the housing is a lift member comprising a substantially circular portion 6 with a radially extending arm 7 which eX- tends through and makes a sliding fit with the slot 5. The portion 6 isthreaded at the bottom thereof and is hollowed out above theV threaded` portion as indicated at 7a. A lifting screw is threaded 8 into the lift member as shown. lt will be noted that the thread is entirely protected from blows or from the weather. 'The projecting port-lon 7 is of gentil erally cruciform section having a central web 9 and sidewise extending webs 10. Ratchet teeth 11 are formed on the webs 10 and a lifting foot 12 is fitted thereon. The lifting foot 12 has a pair of arms 13 which embracethe outwardly.- extending portion 7 these arms 5 having. lugs 14 thereon which lit behind the websllO. The arms 13 are also provided with lugs 1 5 which engage the teeth 11 so as to support the liftingfootat different vertical positions `along the-.radially extending portion 7 of the lift member.

.lt will be noted that the lift member and its radially extending portion 7 are of substantially the same heighth as the housing 3.

lfr desired, the lifting foot 12 may vbe flipped 'over on the top of the lift member as indicated in dotted lines in Figure 2, so as to give additional heighth to the ack. A load may, therefore, be engaged either bv the top face 16 of the liftfmember and immediately 70 above the lifting screw 8 or on the face 17 or the face 18 of the foot 12. f

The screw is provided at its bottom end with a shaft portion 19 which rests on an anti-friction bearing 2O in the base. An internal, gear 21 is secured to the screw and it meshes with planet 'pinions 22 mounted on studs23 secured to the internal gear. The planet pinions mesh with a sun pinion 24 which is carried by the hub 25 of bevel gear 26. The bevel gear rotates freely on'the shaft portion 19. A bevel pinion 27 meshes with the bevel gear and this pinion is mounted on a. shaft 28 whichrotates in the base 2. A socket 29 adapted to engage a suitable operatinghandle is connected to the shaft.

The jack is particularly adapted Afor garage or bns work, and by reason of the gearing employed, it provides a very great mechanical advantage. It will be understood, however, that under heavy loads this type of gearing, while it is effective for elevating the lift member, will also by reason of the very nature of a lifting screw, eXert a very large turning force.V If keys or splines are Vused to resist this turning force, the manufacture ofthe jack is considerably complicatedand the parts will generally be small and likely to be worn away when grit and mnd gets into the jacks By the provision of a slot extending through the housing with a relatively large radially extending portion thereon, these difficulties are done away With and at the same time the radially extending portion is put to another use by reason of the provision of the lifting foot thereon, thus giving the jack a very Wide range.

When a load is applied on the face 16 or ...o the face 1S, the screw is in direct compresL sion. If, however, the load is applied to the face 17, a bending moment is set up. This is resisted by the sliding fit of the lift member in the upper portion of the housingy 3f, g5 and by the screw itself at the loiver portion of the lift member.

It Will be noted that the base is extended out beyond the foot l2 so as to take care of loads thus applied.

o Figure 3 is a modified construction in Which the upstanding post, instead of being circular in cross section, is U shaped and is provided with inwardly `turned flanges 30 which engage corresponding Hat sides 3l on the lift member 32. The lift screw 8a fits inside this lift member in the same manner as does the. screw 8 in the embodiment of Figures l and 2. This construction is particularly desirable in jacks designed for :lo heavy loadsj as it provides considerable strength, especially when the jack is fully extended.

lVe have illustrated and described a preerred embodiment of the invention, but it 35 will be understood that it is not thus limited, as it may be embodied Within the scope of the foilowing claim.

`We claim:

A lifting jack comprising a standard, a

10 screw rotatable Within said standard, means for rotating said screw, a lifting member axially movable' Within 'said standard by said screw, a saddle carrier carried by said liftl ing member at a point above said standard f3 and extending dovvn along the side of said standard, and means at the lower end of said saddle carrier connected toa bottoni portion of said lifting member, said standard having a slot extending lengthwise. therein in which` 5U said last-named means operates.

In testimony whereof We have hereunto set our hands.

CLARENCE J. RODMAN. HAROLD WV. CLARK. 

